Organisation Flashcards
After the left _____ the blood goes through the _____ to the rest of the body.
ventricle, aorta
Blood comes back from the lungs to the _____ via the _____ _____.
heart, pulmonary vein
Briefly describe how an artificial pacemaker works.
Send strong, regular electrical signals to the heart to stimulate it to contract properly.
Describe 2 structural features of arteries
thick muscular walls, elastic layer in walls, narrow lumen.
Describe 2 structural features of capillaries
Narrow, walls only one cell thick.
Describe 2 structural features of veins
Wide lumen, valves
Give 3 adaptations of the red blood cell.
1) it has a biconcave shape for a higher surface area to volume ratio
2) It has no nucleus
3) it has a lot of haemoglobin
Give 3 things that plasma is made up of.
1) water
2) hormones
3) enzymes
4) products of digestion
5) urea
How does being biconcave help red blood cells with their function?
increase Surface area: volume for efficient diffusion.
Humans have a _____ circulatory system.
dual
Name a method to unblock a coronary artery in the heart.
Stent
name the lower chambers of the heart
right and left ventricles.
name the upper chamber of the heart.
right atrium and left atrium
State 2 differences in the blood flowing in arteries and veins.
oxygenated, more nutrients, less waste products in arteries.
State the function of white blood cells.
engulf pathogens, produce antibodies and antitoxins.
Substances can easily_____ through capillaries because they are _____ thick.
diffuse, one cell
the blood comes from the body, back to the _____ via the _____
right atrium, vena cava
The _____ blood is pumped to the lungs via the _____
deoxygenated, pulmonary artery
What 4 things does blood consist of?
Red blood cells, white blood cells, platelets and plasma
what are red blood cells?
biconcave cells that have haemoglobin - carry oxygen
What are the 3 types of blood vessels?
Arteries, Veins and Capillaries
What can be used to replace damaged valves?
biological or mechanical replacement valves
What can cause arteries to narrow.
fatty build up
what do coronary arteries do?
they supply blood to the heart.
what do platelets do?
when tissues are damaged and blood vessels cut, platelets clump together to stop bleeding and block the broken blood vessels.
What do statins do?
reduce cholestrol levels.
what is a dual circulatory system?
It is a system in which the blood passes through the heart twice before completing a cycle.
What is a natural pacemaker?
a group of cells in the right atrium that controls the resting heart rate.
what is plasma in the blood?
Yellow liquid that carries blood cells, proteins and dissolved substances around the body.
What is the function of the valves.
to prevent the backflow of blood.
what is the pigment found in red blood cells that binds to oxygen?
haemoglobin
What is the purpose of the circulatory system?
to pump blood around the body, which contains oxygen, glucose and products of digestion.
What two things are used for respiration?
oxygen and glucose
What type of tissue is the heart walls made up of?
Cardiac Tissue
When the atria contract, where does the blood go?
it goes through the valves and into the ventricles.
Where are the coronary arteries located?
on the outside of the heart.
Which organ system transports substances to and from body cells?
circulatory system
Which side of the heart has deoxygenated blood?
Right
Why is the muscle wall of the left ventricle thicker?
It needs to pump the blood all over the body so it needs to be stronger.
Why do arteries have thicker muscle walls than veins?
to withstand high blood pressure
What are organelles?
subcellular structures
What is a tissue?
a group of similar cells that work together to carry out a particular function
What is an organ?
a group of different tissues that work together to perform a particular function
In plants, what are leaves examples of?
organs
Why can we not just increase the temperature of our bodies to increase the rate of reactions within us?
damage to the cells
would speed up non useful reactions
requires lots of energy
What is a catalyst?
a substance that increases the speed of a chemical reaction without being used up or changed in the process.
What is an example of a biological catalyst?
enzyme
What is an enzyme?
a special type of catalyst made by a living organism
What are enzymes made up of?
long chain of amino acids as they are proteins
What is the name of special region of an enzyme that binds to the substrate?
active site
In order for an enzyme to catalyse a reaction, the active site of the enzyme must be _____________ to the substrate.
complementary
What is the lock and key model?
the idea that for an enzyme to catalyse a reaction, the substrate has to perfectly fit into the active site
What is the induced fit model?
in order for an enzyme to catalyse a reaction, the enzymes active site actually changes shape slightly as it binds to the substrate.
What does the term ‘optimum’ mean for enzyme temperature?
The temperature at which enzyme activity is highest
What affect does extremely high pH have on enzymes?
denatures them
What is the optimum temperature for enzyme activity?
37 C
Explain how increasing the temperature can cause an enzyme to denature.
High temperatures start to break the bonds holding the enzyme together
This causes the enzyme and it’s active site to change shape
This means the enzymes active site will no longer be complementary to the substrate
Which 3 biological molecules do we need in large quantities?
Carbohydrates
Lipids
Proteins
Why do we need carbohydrates?
To provide energy for chemical reactions
Why do we need lipids?
To insulate us and regulate our body temperature
To provide energy for chemical reactions